The most reliable way to convert a GLB to STL is to import the GLB into Blender, the free 3D software, and export it with File > Export > Stl (.stl). Blender supports both importing glTF 2.0 (.glb / .gltf) and exporting STL out of the box, so you don't need to buy any extra software. Before you convert, though, there is one fact you need to know: STL keeps no color or texture information. After conversion, your model is just a shape in a single color.
This article walks you through the conversion step by step, explains what the export settings mean, compares the free options, and covers the alternative to use when you want to keep the colors.
Note: Figmee currently generates figurine-style images and downloadable 3D model data (GLB / 3MF) from the drawings and illustrations you upload. Sales of physical 3D-printed products are Coming Soon.
Why the colors disappear
The cause is that the two formats were designed for different purposes.
GLB (glTF 2.0) is a format defined by the Khronos Group (as of July 2026) for delivering and displaying 3D models efficiently. Alongside the geometry, a single file can contain material information such as base color, metallic, roughness, ambient occlusion, normal maps, and emissive, as well as the texture images themselves (source: Blender Manual - glTF 2.0, as of July 2026).
STL, by contrast, only describes the surface of a solid as a collection of triangles. The official Blender manual explains that the STL file format is useful for exchanging files with CAD software and is commonly used for loading into 3D printing software (source: Blender Manual - STL, as of July 2026). The specification simply has no mechanism for storing materials or textures.
| Item | GLB | STL |
|---|---|---|
| Geometry | Kept | Kept |
| Color and textures | Kept | Not kept |
| Materials (metalness, roughness, etc.) | Kept | Not kept |
| Bones and animation | Can be kept | Not kept |
| Main uses | Web display, game engines, file exchange | CAD, 3D printing |
| File structure | Everything in one file | One file (geometry only) |
In other words, losing the colors isn't a failed conversion. It is exactly what the STL format is specified to do. For a rundown of how each format behaves, see OBJ vs FBX vs STL vs GLB: How to Choose the Right 3D File Format.
How to convert in Blender (about 5 minutes)
- Install Blender (first time only, 5–10 minutes). You can get it for free from blender.org. If it's already installed, skip this step.
- Launch Blender and delete the default cube (20 seconds). Select the Cube in the middle of the scene and press
Xto delete it, so the imported model is easier to see. - Import the GLB with File > Import > glTF 2.0 (.glb/.gltf) (1 minute). The glTF 2.0 add-on is enabled by default, so you usually don't need to install anything. For detailed import steps, see Prototype in Figmee, Refine in Blender: The Complete Guide to Importing GLB Files.
- Check that the model displays correctly (1 minute). Press
.on the numpad (View Selected) to fill the screen with the model. It's fine if it still looks colored at this stage. - Select the objects you want to export (10 seconds). If the model is split into several parts, press
Ato select all. - Choose File > Export > Stl (.stl) (10 seconds).
- Review the export settings and save (1–2 minutes). The table below explains what each setting does.
What the export settings mean
These are the main STL export settings described in the official Blender manual.
| Setting | What it does | Rule of thumb |
|---|---|---|
| Format: ASCII | Writes a text file instead of a binary one | Usually leave it off (binary files are smaller) |
| Batch | Exports each object as a separate STL | Turn it on when you want to print the model in parts |
| Selection Only | Exports only the selected objects | Turn it on when you only want to export part of the scene |
| Scale | Scale factor relative to the world origin | Adjust it when the dimensions don't match |
| Scene Unit | Applies the scene's unit settings to the exported data | Turn it on when you want to work at real-world size |
| Forward / Up | Converts the forward and up axes | Use it when the model is oriented differently in the receiving software |
| Apply Modifiers | Exports the mesh after modifiers are evaluated | Usually leave it on |
| Properties (Viewport / Render) | Chooses whether to use viewport or final render settings | Matters if you use a Subdivision Surface modifier |
On Forward / Up, the official manual explains that Blender uses Y forward and Z up (since the front view looks along the +Y direction), and that it's common for applications to use Y as the up axis, in which case you need to specify -Z forward and Y up. If your exported model ends up lying on its side, check this setting first.
What to do before exporting
Taking care of these three things between steps 5 and 6 will save you rework later.
Delete unneeded parts. A GLB sometimes contains a base, a background plane, or small props you don't need. Removing them after converting to STL is a hassle, so delete them in Blender first. Select the object and press X.
Decide whether to split the model into parts. If you want to print the pieces separately and assemble them later, turn on Batch in the export settings and each object will be written to its own file. If you want to export the whole model as one piece, leave it off.
Decide on the scale. If you know in advance how many millimeters tall you want the model to be, you can get the size right in the slicer in one go. In Blender, press N to open the sidebar, where you can check and enter the selected object's Dimensions as numbers.
Free methods compared
Blender isn't the only way to get an STL. Each method has its strengths and weaknesses.
| Method | Cost | Pros | Cons |
|---|---|---|---|
| Convert in Blender | Free | You can check and fix the shape before converting, and control the settings in detail | Requires installation; there's a learning curve the first time |
| Online conversion service | Mostly free (with limits) | No installation; done in a few clicks | Your file is handed to a third party's server; size limits and feature restrictions apply |
| Open directly in a slicer | Free | Can make the conversion step unnecessary | Supported formats depend on the slicer; check beforehand |
Things to watch out for with online converters
Being able to do everything in the browser is a clear advantage. For a one-off conversion, or when you don't have the time to install Blender, it's a sensible choice. Just keep the following in mind before you use one.
- Uploading means handing your data to a third party's server. If you're working with your own characters or unpublished work, check the service's terms of use, how long files are stored, and whether data is shared with third parties before you use it.
- There are often limits on size or number of uses. Once you go past the free allowance, you may be unable to convert or face long wait times.
- The colors are lost just as they are in Blender. That's not a difference in tool quality; it comes from the STL specification.
- You have limited ways to check the result. Even if the orientation or scale is off, you may not notice right away.
When your slicer can open GLB directly
Some slicers for 3D printers can import formats other than STL directly. In that case, you can skip the conversion step entirely. The most efficient approach is to first check what your slicer can read. Look up the formats your slicer supports, then decide whether you need to convert at all.
For 3D printing, consider 3MF
If you want to hand off print-ready data with the colors intact, 3MF rather than STL is the format to consider.
3MF is described as a 3D printing format that allows design applications to send full-fidelity 3D models to other applications, platforms, services, and printers, and through the Materials and Properties Extension it supports full-color and multi-material definitions. As of July 2026, the latest version is Core Specification v1.4.0, and it has also become an international standard as ISO/IEC 25422:2025 (source: 3MF Consortium - Specification, as of July 2026).
| Use | Suitable format | Why |
|---|---|---|
| Printing in a single color | STL | The widest software support, and the data is light |
| Passing along color information too | 3MF | Color and material definitions are part of the standard |
| Displaying on the web or using in an engine | GLB | Embeds textures and is designed for display |
For an explanation of 3MF itself, see What Is a 3MF File? How It Differs from STL, Supported Software, and When to Use It. For getting ready to print on your own printer at home, see Preparing a 3MF File for Your Home 3D Printer: Slicer Setting Basics. For the prerequisites when sending data made from an illustration to print (thickness, stability, materials), How to 3D Print an Illustration: Data, Thickness, and Material Basics is a useful reference. And for concrete ways to turn a GLB you have into a 3MF while keeping the colors, How to Convert GLB to 3MF: 3 Ways to Make Color-Ready 3D Print Files breaks it down into three routes.
3 things to check after converting
Once you've exported the STL, check these three things before sending it off to print.
1. Dimensions. Because STL only stores geometry, the receiving software may interpret it in different units than you intended. When you load it into your slicer, always check the actual size (how many millimeters tall it is).
2. Orientation. Make sure it isn't lying on its side or upside down. You can fix this with the Forward / Up settings.
3. Whether the surface is closed. For 3D printing, the solid needs to be a closed shape with an inside. If there are holes or flipped faces, the slicer may throw errors or print something you didn't intend. Blender's Remesh modifier (Voxel mode) tries to generate a closed shape, so it is sometimes used for this kind of fix.
What to do when the STL is too heavy
Because STL describes a solid's surface as a collection of triangles, the more faces a model has, the bigger the file gets, plain and simple. AI-generated models and heavily sculpted models can swell to the point where the slicer slows down.
In that case, reduce the face count before exporting with Blender's Decimate modifier. The official manual explains that the Decimate modifier allows you to reduce the vertex and face count of a mesh with minimal shape changes (source: Blender Manual - Decimate Modifier, as of July 2026).
The main control is Ratio in Collapse mode: 1.0 means no change, 0.5 roughly halves the face count, and 0.0 removes every face. The modifier panel shows how many faces will remain, so you can lower the value while watching the number. A good guideline is to go as low as you can without changing how the print looks. Once fine details start to collapse, you've hit the lower limit.
The official manual also notes that you can't see this modifier's changes in Edit Mode. Make your adjustments in Object Mode while watching the result.
Frequently asked questions
Is there a way to keep the colors from disappearing when converting to STL?
Not as long as you stay in the STL format, because the standard has no mechanism for storing color information. If you want to pass along the colors too, use a format that supports color and material definitions, such as 3MF. Alternatively, you can send the shape as an STL and paint the print yourself afterward.
Should I use an online converter or Blender?
For a one-off conversion where you have no concerns about the rights to the data, the convenience of an online converter wins. On the other hand, if you're handling your own character data, converting multiple times, or want to fix the shape before converting, Blender is the better fit. In Blender you can check the dimensions, orientation, and surface condition with your own eyes before exporting, so you'll redo things less often.
Can I go the other way and convert STL to GLB to add color?
The format conversion itself is possible, but the lost colors won't come back. Because STL contains no color information, you'll need to set up materials yourself or paint textures after converting. In Blender, you can import the STL and then paint it with Texture Paint. If you go in thinking "once it's an STL, I'll have to recreate the colors myself," your expectations won't be let down.
My converted STL won't open in my slicer.
First, re-import it into Blender to check whether the file is corrupted. If it imports fine, the problem isn't the format; it may be the slicer's support (such as a file size limit or ASCII support). Turning off Format: ASCII and exporting again as binary sometimes solves it.
Summary
Converting GLB to STL takes two steps in Blender: Import (glTF 2.0), then Export (Stl). It costs nothing, and the biggest advantage is that you can check the shape and dimensions yourself before converting. Online converters are convenient too, but choose them knowing that you're handing your data to a third party and that there are limits.
Most importantly, remember that STL doesn't keep colors. That's the specification, and it doesn't change no matter which tool you use. If you want to pass along color information, use 3MF; if you're using the model on the web or in a game engine, keep it as GLB. Choosing the format based on where the file is going is the approach least likely to go wrong. For more on the GLB format itself, see What Is a GLB File? How to Open, Use, and Convert It, Explained Simply.
